Sometimes, it is indeed desirable to have hysteresis (for example, in a reset circuit). Hysteresis is also useful in avoiding false switching (with noisy or slowly changing signals). Accordingly, several types of hysteresis circuits have been designed and constructed so far.
A disadvantage of using conventional hysteresis circuits lies in that several resistors are needed during the operation of the conventional hysteresis circuits. Accordingly, utilizing a low supply voltage is not practical.
However, it is preferred that the hysteresis circuits function at low power supply voltages and low power consumption. In this way, hysteresis circuits can be made useful in the case of small, portable electronic equipment.
Referring now more specifically to CMOS devices, in certain scenarios, a high-current region exists when CMOS devices are switching (i.e., “through current”). Accordingly, using a conventional hysteresis circuit is not advisable.
Therefore, a need exists to overcome the problems with the prior art as discussed above.